Priming apparatus for internalcombustion engines



f June 24, 1952 K. P. SCHOEPPNER ET AL 2,601,552

PRIMARY APPARATUS FOR INTERNAL-COMBUSTION ENGINES Filed Feb. 16, 1950 3Sheets-Sheet l p 72 yiilffNTOR-S (i y BY WM 5,

June 1952 K. P. SCHOEPPNER ET AL 6 PRIMARY APPARATUS FORINTERNAL-COMBUSTION ENGINES Filed Feb. 16, 1950 5 Sheets$heet 2 pINVENTORS BY W M filo/v7.97

June 1952 K. P. 'SCHOEPPNER ETAL 2,601,562

PRIMARY APPARATUS FOR INTERNAL-COMBUSTION ENGINES- Filed Feb. 16, 1950 3Sheets-Sheet 3' 'IIIIII'IIIIII INVENTORS k144i?! M BY C Jfllor/yeq/Patented June 24, 1952 PRIMIN G APPARATUS FOR INTERNAL- COMBUSTIONENGINES Karl P. Schoeppner, Whitefish Bay, and Colman F. Zaitz, PortWashington, Wis., assignors to Harnischfeger Corporation, Milwaukee,Wis., a corporation of Wisconsin Application February 16, 1950, Serial N0. 144,516

Claims.

This invention relates to priming apparatus for cold starting internalcombustion engines of the two cycle type having separate blowers forsupplying air for scavenging or supercharging and cylinders with pistoncontrolled air inlet ports enclosed in an air box with a blower mountedon the air box to supply air under pressure thereto, said priming meanshaving jets or spray nozzles for discharging volatile priming fuel intothe air box between the blower and the cylinders so positioned that thepriming fuel is entrained in the air at the time the latter enters thecylinders, while the position and direction of the jets assist inpropelling the priming fuel along with the air directly into thecylinders.

In prior methods of cold weather priming and starting of two cycleinternal combustion engines having forced air supply, the priming fuelhas been introduced into the air on the inlet side of the blower. Thishas lacked effectiveness because the volatile fuel becomes so diffusedin the air that by the time it has passed through the blower and the airbox an insufficient concentration of the fuel reaches any one cylinder.By means of the present invention a concentrated charge of high volatilepriming fuel is entrained with the rapidly moving air immediately as itenters the air inlet ports of one or more cylinders when the pistons arein lowered position an action which is aided by the propulsive effect ofthe spraying action itself. When the pistons move upward the air inletports are closed and the injected fuel in relatively high concentrationand air are compressed to ignition temperature.

In the drawings:

Figure 1 is a side view in elevation of a two cycle internal combustionengine with the outer wall of the air box broken away to show the airinlet ports in the cylinder sleeves and showing a priming apparatusconstructed in accordance with the invention,

Figure 2 is a front end view in elevation and partly in section of theengine shown in Fig. 1, with the parts shown in section viewed throughthe plane 2-2 indicated in Fig. 1, Figure 3 is an enlarged detailed rearend view in elevation and partly in section of the priming fuel supplytank viewed through the plane 3-3 indicated in Fig. 1,

Figure 4 is a detailed, tilted, top plan view of the priming fuelinjection pump with a part broken away viewed through the plane 4-4indicated in Fig. 3.

Like parts are identified by the same reference numerals throughout theseveral views.

The priming apparatus of this invention is adapted to assist the coldstarting of compression ignition internal combustion engines of the twocycle type in which the air for combustion is arranged to be supplied byseparate air forcing means. One form of such an engine of the uniflowtype is illustrated in Figs. 1 and 2 of the drawings. The engine thereillustrated is provided with a main engine frame designated generally bythe numeral I. The lower portion of the frame I forms the upper half 2of a crank case closed on the bottom by a pan 5, while the upper part ofthe frame I forms an air box 3 which serves also as an entablature forthe mounting of three unitary. water-jacketed cylinder sleevesdesignated generally by the numeral 4, two of which appear in Fig. 1.

Mounted for reciprocation within the cylinder barrels B of the sleeves 4are pistons 6, which are connected by rods 1 with a crank shaft, notshown, mounted in known fashion within the crank case. The barrels 8 areprovided with circumferential belts II] of increased thickness piercedby circumferentially spaced air inlet ports 9 positioned to be uncoveredby the pistons 6 at the lower ends of their strokes, thus providing airadmission passages extending from the air box 3 into the interior of thebarrels 8. The sleeves 4 are closed at the top by heads I I joinedsecurely to the barrels 8 to form combustion chambers above the pistons6. The heads I I are formed to closely fit openings provided therefor inthe upper wall of the air box 3 so as to securely position the upperends of the sleeves 4 and to close the upper end of the air box 3against escape of air therefrom.

Mounted within the heads II, as shown, are exhaust valves I2 arranged tobe actuated in timed relation to the rotation of the crank shaft, bymeans not shown, so as to be opened when the pistons 6 are in the lowerparts of their strokes. Exhaust gas, permitted to escape by the valvesI2, is carried away through exhaust ports I3 and exhaust manifold I4.The lower ends of the sleeves 4 are received in closely fittingrelationship to openings provided therefor in a barrier I5 in the frameLwhich barrier divides the crank case from the air box 3. In this waythe sleeves 4 are securely positioned at their lower ends and the lowerwall of the air box 3 is closed against escape of air therefrom.

The barrier I5 is ported as shown at It to admit coolant fluid to thecooling spaces surrounding barrels 8 formed by lower cooling jackets IT.The jackets I1 are sealed at their lower ends by gaskets as shown andare hermetically joined with the belts at their upper ends. Belts It] inturn are provided with vertical coolant transfer passages l3 whichalternate with the air inlet passages 3 around the circumference of thebelts Ill. The coolant transfer passages l8 extend upwardly into coolingspaces surrounding the upper parts of the barrels 8 formed by uppercooling jackets I3. Coolant delivered in the space enclosed by thejackets l3 escapes upwardly therefrom through passages provided thereforin head II.

The air box 3 is closed at its ends against escape of air by continuousend walls at its back by a continuous back wall and at its front by afront wall which is continuous except for a main air entrance 20. Theair entrance is, however, tightly joined with the discharge port of apositive displacement blower 2! having a casing 22 within whichintermeshing impellers 23 are caused to rotate by a gear train connectedwith the crank shaft but not shown. Thus when the crank shaft rotates,air is drawn into the blower 2| through an air intake 24 and deliveredunder pressure into the air box 3. The air under pressure within the airbox 3 may escape therefrom only through the cylinder air inlet passages9 when the pistons B are in the lower parts of their strokes. Thedisplacement of the blower 23 for each revolution of the crank shaft inaccordance with known practice is made such as to insure substantiallycomplete scavenging of exhaust gases from the cylinders each time theparts assume exhaust position. As a result rapid and forceable entranceof air through the ports 3 takes place each time a piston 6 reaches thebottom of its stroke and this condition prevails, although in adiminished degree due to leakage in the blower 2|, even at the time ofstarting of the engine, after not more than one or two revolutions ofthe crank shaft.

For the purpose of introducing volatile priming fuel, when required, areservoir 25 is conveniently mounted as shown in Fig. 1 and connected bya delivery pipe 26 with a manually operated priming pump generallydesignated by the numeral 28. The pump 28 is provided with a barrel 35.As illustrated in Fig. 4 the barrel ii is broken away to show primingfuel pump piston 30 connected to hand knob 29 by piston rod 3|.

Pump 28 is connected to priming fuel supply pipes 32 by a manifold 21.As shown in Fig. 1 supply pipe 32 is connected with priming fuelinjection jet or spray nozzle 33 and supply pipe 36 connects nozzle 33with nozzle 34.

In the operation of the apparatus shown, referring to Fig. 1, volatilepriming fuel supplied to tank 25 is drawn through pipe 26 into manifold21 by hand operation of priming pump 28, operated by hand knob 29. Frommanifold 21 the priming fuel is forced through supply pipes 32 to jetsor spray nozzles 33 and 34. Nozzle 33 is shown directly opposite one ofports 9, evently spaced around cylinder sleeves 4. A view in sideelevation of jet 33 is illustrated in Fig. 2 in which also areillustrated cylinder sleeves 4, air box 3, air blower 2| and enginepiston 6. Air entering blower 2|, through intake 24, is forced throughentrance 20 into air box 3 by the action of pump impellers 23. Whenpiston 6, actuated by the engine starting motor, moves downward andclears air inlet port 3, priming fuel ejected under pressure from nozzle33 is entrained in the air forced out from air 4 box 3 through ports 3and projected into cylinder barrels 8.

Petroleum ether is the preferred volatile priming fuel. When it isdesired to start the engine in cold weather the operator presses theswitch button of the engine starting motor (not shown) with one handwhile actuating the priming fuel injection pump with the other hand. Twoto three revolutions of the crank shaft generally are sufficient tostart the engine even in extremely cold weather.

It will be noted that with the improved priming apparatus of thisinvention the volatile priming fuel is injected into a comparativelysmall volume of air in the air box at or in the near vicinity of thecylinder air inlet ports. This smallvolume of air is easily andimmediately saturated by the spray and the saturated air is propelledimmediately into the cylinder so that the assistance of thesupplementary starting fuel is available at the very outset of thecranking operation of the engine at a time when the available batterycharge for cranking purposes is at a maximum and the rate of turning ofthe engine is greatest.

This is in strong contrast with the conditions prevailing where thepriming fuel is supplied as heretofore at a point on the air inlet sideof the blower. Introduction of the priming fuel ahead of the blowerresults in the necessity of establishing an effective concentration ofvapor throughout the entire air content of the air inlet to the blower,the blower itself and the air box before any assistance to the firing ofa cylinder is made available. such demands several revolutions ofcranking action, by which time the battery charge becomes substantiallydiminished and the possibility of successful starting is pro tantodiminished.

Under conditions of actual comparison an engine provided with the novelpriming apparatus of this invention has therefore been found to startmore easily and certainly under cold weather conditions than enginesequipped with priming apparatus as heretofore employed.

We; claim: 7

1. In an improved priming apparatus for an internal combustion engine ofthe two cycle type having an air box, cylinder sleeves mounted in saidbox, air inlet ports in said sleeves forming a communicating passagebetween said air box and the interior of said sleeves, pistons withinsaid sleeves movable to cover said air inlet ports when in upperposition and to clear said ports when in lowered position, and an airforcing means connected to said air box to deliver a continuous flow ofair under pressure thereto to continuously maintain pressure therein inexcess of atmospheric pressure, the improvement in said primingapparatus for such an engine which comprises priming fuel pressureapplying means, spray nozzles connected thereto to be supplied thereby,said nozzles being positioned between said air forcing means and saidair inlet ports of said engine, at least one of said nozzles beingpositioned opposite inlet ports of at least one of the engine cylindersand directed to inject priming fuel through said air inlet ports intosaid cylinder.

2. In an improved priming apparatus for an internal combustion engine ofthe two cycle type having an air box, cylinder sleeves mounted in saidair box, air inlet ports in said sleeves forming a communicating passagebetween said air box and the interior of said sleeves, pistons withinsaid sleeves movable to cover said air inlet ports when in upperposition and to clear said ports when in lowered position, and airforcing means connected to said air box to deliver a continuous flow ofair under pressure thereto to continuously maintain pressure therein inexcess of atmospheric pressure, the improvement in said primingapparatus for such an engine which comprises priming fuel injection jetsmounted in said air box in position opposite air inlet ports of at leastone of said cylinders having discharge openings positioned to directpriming fuel toward said air inlet openings and means for supplyingvolatile priming fuel to said jets under pressure.

3. In an improved priming apparatus for an internal combustion engine ofthe two cycle type having an air forcing means communicating with an airbox to continuously maintain pressure therein in excess of atmosphericpressure, air ports forming a communicating passage between said box andthe interior of the cylinders of said engine, the improvement in saidpriming apparatus which comprises spray nozzles mounted in said air box,and priming fuel forcing means connected thereto, said spray nozzlesbeing positioned to direct priming fuel through said air ports into theinterior of said cylinders.

4. In an improved priming apparatus for an internal combustion engine ofthe two cycle type having an air forcing means communicating with an airbox to continuously maintain pressure therein in excess of atmosphericpressure, said air box being positioned to encompass cylinder barrels ofsaid engine, and air ports within said box communicating with theinterior of the cylinder barrels of said engine, the improvement in saidpriming apparatus which comprises spray nozzles mounted in said air box,and priming fuel forcing means connected thereto, said nozzles beingpositioned between said air forcing means and said air ports, andpositioned to direct priming fuel into the air in said box in thevicinity of said air ports.

5. In an improved priming apparatus for an internal combustion engine ofthe two cycle type having an air forcing means communicating with an airbox to continuously maintain pressure therein in excess of atmosphericpressure, said air box being positioned to encompass cylinder barrels ofsaid engine, air ports within said box communicating with the interiorof the cylinder barrels of said engine, the improvement in said primingapparatus for such an engine which comprises priming fuel injectionnozzles mounted in said air box between said air forcing means and saidair outlet ports and positioned to direct priming fuel toward said airports, and manually actuated means for supplying priming fuel to saidnozzles under pressure.

KARL P. SCHOEPPNER. C'OLMAN F. ZAITZ.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS

